Update npm packages

Bump npm version installed by travis
Update package-lock for latest npm version
Bump packages versions and clean-up unused
Missing datatables.js images to avoid warnings

.travis.yml

@@ -11,6 +11,7 @@ cache:
   - "$TRAVIS_BUILD_DIR/code/espurna/node_modules"
 install:
 - pip install -U platformio
+- npm install -g npm@latest
 - cd code ; npm install --only=dev ; cd ..
 env:
   global:

code/gulpfile.js

@@ -31,7 +31,6 @@ const runSequence = require('run-sequence');
 const through = require('through2');
 
 const htmlmin = require('gulp-htmlmin');
-const uglify = require('gulp-uglify');
 const inline = require('gulp-inline');
 const inlineImages = require('gulp-css-base64');
 const favicon = require('gulp-base64-favicon');

code/package.json

@@ -1,25 +1,23 @@
 {
   "name": "esp8266-filesystem-builder",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "description": "Gulp based build system for ESP8266 file system files",
   "main": "gulpfile.js",
   "author": "Xose Pérez <xose.perez@gmail.com>",
   "license": "GPL-3.0",
   "devDependencies": {
-    "del": "^2.2.1",
     "gulp": "^3.9.1",
     "gulp-base64-favicon": "^1.0.2",
     "gulp-crass": "^0.2.2",
     "gulp-css-base64": "^1.3.4",
     "gulp-csslint": "^1.0.0",
     "gulp-gzip": "^1.4.0",
-    "gulp-htmllint": "0.0.14",
-    "gulp-htmlmin": "^2.0.0",
+    "gulp-htmllint": "0.0.16",
+    "gulp-htmlmin": "^5.0.1",
     "gulp-inline": "^0.1.1",
-    "gulp-remove-code": "^3.0.2",
-    "gulp-rename": "^1.3.0",
+    "gulp-remove-code": "^3.0.4",
+    "gulp-rename": "^1.4.0",
     "gulp-replace": "^1.0.0",
-    "gulp-uglify": "^1.5.3",
     "map-stream": "0.0.7",
     "run-sequence": "^2.2.1"
   }